GPR40 agonists are suitable for the prophylaxis and/or therapy of metabolic diseases, such as diabetes, more specifically type 2 diabetes mellitus, and conditions associated with the disease, including insulin resistance, obesity, cardiovascular disease and dyslipidemia. GPR40 modulators comprising an optically active dihydrobenzofuran ring and processes for their preparation are known in the art, for example, from WO 2008001931 and WO 2012072691. WO 2012111849 describes a method for preparing optically active GPR40 modulators comprising an asymmetric hydrogenation reaction in the presence of a ruthenium complex applied to a benzofuran derivative used as a building block.